Loan and Lease Receivables - Summary of Minimum Annual Lease Payments for Lease Financing Receivables (Details) $ in Thousands	Mar. 31, 2021 USD ($)
Receivables [Abstract]
2021	$ 68,542
2022	77,452
2023	56,185
2024	34,356
2025	19,047
Thereafter	3,596
Total	$ 259,178

Finance leases future minimum payments receivable.

No definition available.

Name:	by_FinanceLeasesFutureMinimumPaymentsReceivable
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Finance leases future minimum payments receivable in due thereafter.

No definition available.

Name:	by_FinanceLeasesFutureMinimumPaymentsReceivableInDueThereafter
Namespace Prefix:	by_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Finance leases future minimum payments receivable in four years.

No definition available.

Name:	by_FinanceLeasesFutureMinimumPaymentsReceivableInFourYears
Namespace Prefix:	by_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Finance leases future minimum payments receivable in next twelve months.

No definition available.

Name:	by_FinanceLeasesFutureMinimumPaymentsReceivableInNextTwelveMonths
Namespace Prefix:	by_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Finance leases future minimum payments receivable in three years.

No definition available.

Name:	by_FinanceLeasesFutureMinimumPaymentsReceivableInThreeYears
Namespace Prefix:	by_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Finance leases future minimum payments receivable in two years.

No definition available.

Name:	by_FinanceLeasesFutureMinimumPaymentsReceivableInTwoYears
Namespace Prefix:	by_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Finance leases future minimum payments receivable remainder of fiscal year.

No definition available.

Name:	by_FinanceLeasesFutureMinimumPaymentsReceivableRemainderOfFiscalYear
Namespace Prefix:	by_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

No definition available.

Name:	us-gaap_ReceivablesAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration